Web aligning device



Nw. i, 1966 E. E.. BoAsE WEB ALIGNING DEVICE 2 SheetS-Sheet l Filed July27, 1964 Nov. 1, 1966 E. E. BoAsE WEB ALIGNING DEVICE 2 Sheets-Sheet 2Filed July 27, 1964 E 1.../ j. mm G mk om mm mm mm wmmmm Nw MR. wm. Jfw@ K fili 111 ,F EE M, l Il hl III 4 Il mw .v Ihm im@ l! m. l /M w 7 m,7 IW Im vATToRw/SY AND AGENT United States Patent O 3,282,487 WEBALIGNING DEVICE Elmer E. Boase, Rochester, NX., assignor to EastmanKodak Company, Rochester, N.Y., a corporation of New Jersey Filed July27, 1964, Ser. No. 385,170 17 Claims. (Cl. 226-190) The presentinvention relates to web guiding apparatus and more particularly toapparatus for automatically correcting angular displacement of a movingweb, such as paper, fabric or similar mate-rials.

In guiding a moving web through a predetermined path, it is customary toprovide at least one control roller that can be oriented by any angulardisplacement of the web to compensate for such displacement. Such acontrol roller can be located in any portio-n of the web path and isusually located yin a position Where the web path changes direction.Complex electrical, hydraulic land pneumatic control devices have -beendevised to aut-omatically correct |for such displacement of a mo-vingweb. In most of these devices, Aan independent drive means is used toproperly orient the control roller in response to any detecteddisplacement of the web.

In the present invention two roller assemblies are `used, each having atleast one :roller that is movable about a pivotal axis in response toany angular displacement of the Web for automatically correcting forsuch displacement. In many instances it is desirable to convey the webfrom one type `of apparatus to another, for example, from `a printingdevice to a cutting device in which the continuous web spans t-he spaceIbetween the devices. If these devices are not precisely aligned, thereis some lateral displacement of the web lin its movement from the onedevice to the other. The invention described hereinafter is particularlyadapted to such an arrangement in that one of the roller assemblies canbe associated with each of the devices and is capable of compensati-ngnot only Ifor web ydispl-acement but also for any translational orrotational lmisalignrnent of the devices. Such correction isaccomplished by the invention in that the movable roller in the firstassembly :is .responsive to any change in the angular displacement inthe web between the two devices and the second roller assembly isresponsive to any change in the path llength lof the web between thedevices as well as any residual :angular displacement of the web.

A primary object of the invention is to automatically correct angulardisplacement of a moving web by means which is self-actuating and has ashort response time.

Another object of the invention is t-oprovide an apparatus forautomatically correcting angular displacement of a moving web bytranslational and/ or rotational displacement of one web support devicewith respect to another.

These and other objects and advantages of the invention will be apparentto those skilled in the art by the description of a preferred embodimentof the invention which follows.

Reference is now made to the accompanying drawings wherein likereference numerals and characters design-ate like parts and wherein:

FIG. l is a diagrammatic View of two roller assemblies shown in spacedrelation which is indicative of different devices on which each assemblycan be mounted;

FIG. 2 is a side View `of the roller assembly shown at the right-handside of FIG. 1;

FIG. 3 is a front elevational view ofthe roller assembly shown in FIG.2;

FIG. 4 is a side view of the roller Kassembly shown at the left-hand.side of FIG. 1;

FIG. 5 is a front elevational view of the roller assembly shown in FIG.4; and

FIG. 6 is a partial sectional view taken on the line 6 6 in FIG. 5.

With reference to FIG. 1 ia first roller assembly 10 can be fixed inproper relation to a device 72 that is used to accomplish a step orprocess with respect to the web 11. A second roller assembly 12 isarranged on another device 73 which coacts with the web 11 and is spacedfrom that on which the roller assembly 10 is mounted. The web 11 can bemoved through the path formed by the rollers associated with eachassembly as described in more detail hereinafter in `any well knownmanner.

The first roller assembly 10` comp-rises a U-shaped bracket 15 whichincludes a base 16 that is secured to device 72 and a pair of spacedbearing supports 17. An upright partition 18 extends from the base `andbetween the supports 17 to make the bracket 15 more rigid. Roller 25 ismounted between the supports 17 in bearings not shown; is freelyrotatable and serves to Iguide the incoming web 11 from a substantiallyvertical direction to a substantially horizontal direction.

Steering roller 26 c-omprises `a longitudinal shaft member 27 that isfixed `at its ends in the supports 17, a pivotal sleeve 31 and a webroller 35. The central portion 28 of the shaft 27 is preferably squarein cross-section and is provided with -a central bore Z9 in wln'oh abearing sleeve 3) is arranged. Approximately concentric with the shaft27 is a sleeve 31 which is pivotally mo-unted with respect to shaft 27by means Aof a pin 32 that is mounted in bearing sleeve 3d and at itsends is journa-led in a pair of bearing members 33 in the sleeve 31.Each end of sleeve 31 carries a bearing 34 for rotatably supporting theweb roller 35. With reference to FIG. l, it will be noted that the yaxis36 of pin 32 is substantially perpendicular to the center line of theincoming web 11. As explained in more detail hereinafter, the web roller35 can rotate about its axis 38 Iand can also be moved about t-hepivotal `axis 36 of pin 32 in a vertical plane that passes through theaxis 38.

The roller assembly 10 also includes Ka freely rotatable roller 37 thatis mounted between the supports 17 in substantially the same manner asthe roller 25. The roller 37 receives the moving web from the web roller35 and guides it into a first path or plane that is substantiallyperpendicular to that of the incoming web 11. The outgoing portion 13lof the Web 11 spans the space between the first roller assembly lil andthe second roller assembly 12.

The second roller assembly 12 comprises a bracket 4t) having anextension 41 that is secured to the secon-d device 73. A support arm 42depending from extension 41 cooperates with Ia pivotal connection 43, asshown in FIG. 6, for lsupporting a U-s'haped bracket 44 having spacedarms 45 between which a pair of rolle-rs 46 and 47 are rotatablymounted. The Ibracket 44 is provided with a yoke 4S into which the:support arm 42` extends. The yoke 48 carries a pair of bearings 49 inwhich a stub shaft 5t) that is carried by arm 42 is journaled. In orderto limit arcuate movement of bracket 44 relative to bracket 40, asdescribed hereinafter, the bracket 40 carries a pin 51 which extendsinto an arcuate slot 52 in one arm `of the yoke 48.

Roller 46 is a solid roller and is rotatably mounted in bearings thatare carried by the arms 45. The second steering roller 47 comprises ashaft 53, a pivotal sleeve 58 and a web roller 61, .the shaft 53 beingpinned to one of the arms 45, as designated by the numeral 54, so thatthis shaft is held against any rotation. The central portion 55 of shaft53 carries a sleeve bearing 56 for a pintle 57. The pivotal sleeve 58 isjournaled on the ends of ,pin-tlc 57 by means of a pair of bearing-members 59 and at each end thereof carries a bearing 60. The web roller61 is provided with an internal diameter 62 that engages :the bearing 60so that the roller is rotatable about an 72 that is angularly arrangedwith respect 4to the intersection of the -axis 73 olf shaft 53 and theaxis 74 of pintle 57. Each end of web roller r6d is provided with aflange 63 which is formed as a separate member insertable into the endof the roller or formed integral with the roller. The roller 47 cantherefore rotate freely about its axis 72 and can also pivot in ahorizontal plane about the axis 74 of the pint-le 57 which issubstantially perpendicular to the pivotal axis ot the brackets 40 and44 which is designated by the numeral 75.

Since the second roller assembly permits movement of the roller 47 aboutthe laxis 74 of the pintle 57 and also is rotatable about the axis 75 asa complete unit, it is necessary that the assembly be well balanced inorder to make the device independent of any gravity effect. In order toaccomplish this, countenweights y65 and 6o are secured to the surfaces67 and 68 of the bracket 44 by means of screws 69 .and 70. By means ofsuch counterweights, the second roller assembly l2 can be balanced inassembly and before it is mounted on the second device 73.

As described above, bracket 15 of the first roller assembly 10 can besecured -to the tirst device, generally designated by the numeral 72 inFIG. l, and the bracket 40 of the second roller assembly 112 can besecured to the second device generally designated by the numeral 73.While the devices 72 and 73 are shown and described as being .separatedevices, the aligning function of the system is the same even if the tworoller assemblies were mounted in spaced relation on the same device. Ineither case, it can be yreadily appreciated that one assembly could be-mounted with respect to the other such that the :rollers 26 and 37 arenot aligned with their axes exactly parallel to those of rollers 46 and47. In addition, the assemblies 10 and 1-2 could be mounted so that theyare transversely misali-gned or even with one assembly rotated slightlywith respect to the other. This means that the intermediate portion 13of the web can be singularly displaced due to Aany lateral misalignmentof the asscmblies as Well as twisted where there is rotation of oneassembly with respect to the other. It is for conditions such as thesethat the roller assemblies 10 and 12 described hereinabove provide ormaintaining the out-going length of the web in a position that isautomatically corrected for any such misalignment.

The intermediate .portion .13 of the web on leaving roller 37 is forcedto run between the anges 63 on the roller 47. It there is any angulardisplacement of the web between these two rollers, the side forceexerted against the ange corresponding to the direction in which thedisplacement takes pla-ce causes the bracket 44 to pivot about the axis75 of stub shaft 50' until this force is negated by the position thatthe roller assembly 12 then assu-mes. It will be noted from FIGS. 1 and5 that the axis 75 of stub shaft 50 is on the neutral axis of the webbetween the roller 46 and a fixed idler roller 76. As a result, theoutgoing web leaving roller 46 is always maintained in the same relationto this pivot-al axis. When the intermediate portion 13 of the web 11 isangularly displaced, an increase in path length of the web between therollers 37 and 47 actually occurs. The increase in path length theneiects the -force required to rotate or i pivot the assembly 12 aboutthe axis 475 of `stub shaft 50 to minimize the path length.

In addition to the pivotal movement of the roller assembly 12, theroller 47 ,pivots about the axis 74 of pintle 57 until the `rotationalaxis 72 of the Web roller 61 is perpendicular to the direction of webmovement. Once this has been accomplished, the web is in a position ofequilibrium on roller 47 and does not exert any side force on either ofthe lianges 63 except that amount of force necessary to move theassembly 12 to maintain the por- 4 tion 13 of web 411 in a twistedhelical shape. The force that causes roller 47 to move into a positionof equilibrium with respect to the incoming web is proportional to thenumber of degrees that the web is angularly displaced. In order tosupplement the restoring force necessary to overcome the static frictionas the ,point of perpendicularity is approached, the roller 47 has itsgeometric axis 72 arranged at an an-gle with respect to its rotationalaxis 73 in order to cause a roller sur-face wobble. As described above,the .geometric axis 72 passes through the point of intersection of theaxis 73 of shaft 53 and tfhe axis 74 of .pintle 57. The wobble effectobtained with this structure causes the roller 47 to oscillate about theperpendicular position it assumes relative to the web and therebynullii'ies the effective friction between the roller and the web.

With any angular displacement of the portion 13 of the web, the roller26 acts as a tension equalizing or steering roller. With any suchdisplacement, roller `26 tilts at an angle about the axis 36 of pin 32to allow the web to turn in the same direction as .the roller 47 and atthe same time maintains the level of tension in each edge of the web ata constant value.

From the foregoing description it .should be readily appreciated thatthe system is a passive device requiring no external power and iscapable of correcting angular and/ or translational displacement of amoving web. Further, the system 'has proven to be especially useful withwide, thin webs that resist other methods of alignment correction andnormally require very close angular tolerances between the rollersforming the web path in order to prevent imistracking of the web. Itshould be apparent to .those skilled in .the art that the systemdescribed hereinabove can be used to advantage in many applications Iforcontrolling displace-ment of a moving web and While a-prefe'rredembodiment of the invention has been described, the invention is not tobe limited to such embodiment but is of a sco-pe as defined by Itheappended claims.

I claim:

1. Apparatus for maintaining lateral alignment of a moving web,comprising in combination:

a irst roller assembly for engaging the web and guiding it from a firstpath into a second path substantially perpendicular to that of saidiirst path, said first assembly including at least one web engagingroller mounted for rotation about its longitudinal axis and for pivotalmovement about an axis that is substantially perpendicular to the centerline of said web in said first path in response to any angulardisplacement of said web in said second path for equalizing the tensionin the edges of said web; and

a second roller assembly for engaging said web in said second path andguiding it into an outgoing path that is substantially parallel to saidsecond path, said second assembly including at least one steering rollerunit comprising a member including a pivotal bearing having a pivot axiswhich is substantially perpendicular to said second path, a cylindricalsleeve mounted on said pivotal bearing for pivotal movement in responseto any angular displacement of said web in said second path, and a webguiding roller mounted for rotation on said sleeve about a rotationalaxis and for pivotal movement as a unit with said sleeve about saidpivot axis, the

rotational axis of said web guiding roller being angularly disposed withrespect to the axis of said sleeve and substantially perpendicular tothe axis of said pivotal bearing;

said second assembly being movable about an axis, substantiallyperpendicular to the Irotational axis of said web guiding roller andsubstantially coincident with the extended center line of said web insaid outgoing path, to compensate for any change in path length betweensaid first and second roller assemblies;

whereby changes in the lateral alignment of the moving web arecorrected.

2. Apparatus in accordance with claim 1 wherein said member has an axissubstantially perpendicular to the center line of said web in saidsecond path and the rotational axis of said web guiding roller isangularly disposed relative to the point of intersection of the axis ofsaid member and the pivot axis of said pivotal bearing.

3. Apparatus in accordance with claim 1 wherein the pivot axis of saidpivotal bearing is substantially perpendicular to the axis of saidsecond roller assembly.

4. Apparatus in accordance with claim 1 wherein said web guiding rolleris provided with end flanges against which a force is exerted by anylateral translation of the portion of said web between said first andsecond roller assemblies for moving said second roller assembly in adirection to maintain said portion of said web in a twisted helicalshape.

5. Apparatus in accordance with claim 1 wherein the angular dispositionof the rotational axis of said web guiding roller causes the latter tooscillate about the axis of said member for nullifying the effect offriction when said web guiding roller is in a position of equilibrium.

6. Apparatus for maintaining lateral alignment of a moving web,comprising in combination:

a lirst roller assembly for engaging the web and guiding it from a tirstpath into a second path substantially perpendicular to that of said rstpath, said irst assembly including at least one web engaging rollermounted for rotation about its longitudinal axis and for pivotalmovement about an axis that is substantially perpendicular to the centerline of said web in said rst path in response to any angulardisplacement of said web in said second path for equalizing the tensionin the edges of said web;

a rotatable steering roller for engaging said web in said second pathand guiding it into a third path substantially perpendicular to saidsecond path, said steering roller having a rotational axis and beingmovable about an axis, substantially perpendicular to said rotationalaxis, in response to any angular displacement of said web in said secondpath;

a rotatable idler roller for engaging said web leaving said steeringroller and guiding it into an outgoing path substantially perpendicularto that of said third path; and

means for mounting said steering roller and said idler roller formovement as a unit about an axis substantially perpendicular to therotational axis of said steering roller in response to any change inpath length of said web between said first roller assembly and saidsteering rollers, whereby changes in the lateral alignment ofthe web arecorrected.

7. Apparatus in accordance with claim 6 wherein said one rollercomprises a fixed member having a central pivotal bearing whose axis issubstantially perpendicular to the center line of said incoming web, acylindrical sleeve mounted on said pivotal bearing and a web engagingroller rotatably mounted on said sleeve.

8. Apparatus in accordance with claim 6 wherein said steering rollercomprises an axial, xed member having a central pivotal bearing whoseaxis is substantially perpendicular to the axis of said second rollerassembly, a cylindrical sleeve mounted on said pivotal bearing and a webguiding roller rotatably mounted on said sleeve.

9. Apparatus in accordance with claim 8 wherein said web guiding rolleris rotatable about an axis that is angularly disposed relative to theaxial center line of said sleeve at the point of intersection of theaxial center line of said fixed member and the center line of saidpivotal bearing.

10. Apparatus in accordance with claim 9 wherein said web guiding rolleris provided with end flanges against which a force is exerted by anylateral translation of the portion of said web between said first rollerassembly and said steering roller for moving said mounting means in acorresponding direction to maintain said portion of said web in atwisted helical shape.

11. Apparatus in accordance with claim 9 wherein the angular dispositionof said web guiding roller causes the latter to oscillate about the axisof said fixed member for nullifying the etect of friction when saideccentric roller is in a position of equilibrium.

12. Apparatus for maintaining lateral alignment of a moving web,comprising in combination:

a first rotatable steering roller for engaging the web and guiding itfrom a irst path into a second path substantially perpendicular to thatof said first path and mounted for rotation about its longitudinal axisand for pivotal movement about an axis that is substantiallyperpendicular to the center line of said web in said second path, inresponse to any angular displacement of said web in said second path forequalizing the tension in the edges of said web;

a first rotatable idler roller for engaging the web in said second pathand guiding it into a third path substantially perpendicular to that ofsaid second path;

a second rotatable steering roller for engaging said web in said thirdpath and guiding it into a fourth path substantially perpendicular tosaid thi-rd path, said second steering roller having a rotational axisand being movable about an axis substantially perpendicular to saidrotational axis in response to any angular `displacement of said web insaid third path;

a second rotatable idler roller for engaging said web in said fourthpath and guiding it into an outgoing path substantially perpendicular tothat of said Afourth path; and

means'for mounting said second steering roller and said second idlerroller for movement as a unit about an axis substantially perpendicularto that of said second steering roller, said unit being movable inresponse to any change in path length of said web between said firstidler roller and said second steering roller; whereby changes in thelateral alignment of the moving web are corrected.

13. Apparatus in accordance with yclaim 12 wherein said first steeringroller comprises an axial, fixed member having a central pivotal bearingwhose axis is substantially perpendicular to the center line of saidincoming web, a cylindrical sleeve mounted on said pivotal bearing and aweb engaging roller rotatably mounted on said sleeve.

14. Apparatus in accordance with claim 12 wherein said second steeringroller comprises an axial, fixed member having a central pivotal bearingwhose axis is substantially perpendicular to the axis of said mountingmeans, a cylindrical sleeve mounted on said pivotal bearing and a webguiding roller rotatably mounted on said sleeve.

15. Apparatus in accordance with claim 14 wherein said web guidingroller is rotatable about an axis that is angularly disposed relative tothe axial center line of said sleeve at the point of intersection of theaxial center line of said fixed member and the center line of saidpivotal bearing.

16. Apparatus in accordance with claim 14 wherein said web guidingroller is provided with end anges against which a force is exerted byany lateral translation of the portion of said web between said rstidler roller and said second steering roller for moving said mountingmeans in a corresponding direction to maintain said portion of said Webin a twisted helical shape.

17. Apparatus in accordance with claim 14 wherein said mounting meansincludes means for balancing said mounting means to make the latterindependent of any gravity effect.

3 References yCited by the Examiner UNITED STATES PATENTS 2,82l,3871/1958 Faeber 226-3 5 2,989,265 6/ 1961 Selsted 226-21 X M. HENSON WOOD,J R., Primary Examz'er.

R. A. SCHACHER, Assistant Examiner.

6. APPARATUS FOR MAINTAINING LATERAL ALIGNMENT OF A MOVING WEB,COMPRISING IN COMBINATION: A FIRST ROLLER ASSEMBLY FOR ENGAGING THE WEBAND GUIDING IT FROM A FIRST PATH INTO A SECOND PATH SUBSTANTIALLYPERPENDICULAR TO THAT OF SAID FIRST PATH, SAID FIRST ASSEMBLY INCLUDINGAT LEAST ONE WEB ENGAGING ROLLER MOUNTED FOR ROTATION ABOUT ITSLONGITUDINAL AXIS AND FOR PIVOTAL MOVEMENT ABOUT AN AXIS THAT ISSUBSTANTIALLY PERPENDICULAR TO THE CENTER LINE OF SAID WEB IN SAID FIRSTPATH IN RESPONSE TO ANY ANGULAR DISPLACEMENT OF SAID WEB IN SAID SECONDPATH FOR EQUALIZING THE TENSION IN THE EDGES OF SAID WEB; A ROTATABLESTEERING ROLLER FOR ENGAGING SAID WEB IN SAID SECOND PATH AND GUIDING ITINTO A THIRD PATH SUBSTANTIALLY PERPENDICULAR TO SAID SECOND PATH, SAIDSTEERING ROLLER HAVING A ROTATIONAL AXIS AND BEING MOVABLE ABOUT ANAXIS, SUBSTANTIALLY PERPENDICULAR TO SAID ROTATIONAL AXIS, IN RESPONSETO ANY ANGULAR DISPLACEMENT OF SAID WEB IN SAID SECOND PATH; A ROTATABLEIDLER ROLLER FOR ENGAGING SAID WEB LEAVING SAID STEERING ROLLER ANDGUIDING IT INTO AN OUTGOING PATH SUBSTANTIALLY PERPENDICULAR TO THAT OFSAID THIRD PATH; AND MEANS FOR MOUNTING SAID STEERING ROLLER AND SAIDIDLER ROLLER FOR MOVEMENT AS A UNIT ABOUT AN AXIS SUBSTANTIALLYPEREPNDICULAR TO THE ROTAIONAL AXIS OF SAID STEERING ROLLER IN RESPONSETO ANY CHANGE IN PATH LENGTH OF SAID WEB BETWEEN SAID FIRST ROLLERASSEMBLY AND SAID STEERING ROLLERS, WHEREBY CHANGES IN THE LATERALALIGNMENT OF THE WEB ARE CORRECTED.